One would think that two all-wheel-drive, twin-turbocharged Porsches would be similar machines. Perhaps 25 or even five years ago, that would have been the case. But times have changed. We're not here to debate the philosophical merits or demerits earned by Porsche injecting a big sport/utility into its lineup. That's over; the vehicle is here. And since the company now offers two ways to sell you 450 horsepower, we couldn't pass up the opportunity to compare them and play with the numbers.

By now, you're familiar with the Cayenne; it's an all-new and distinct product, although it shares platform architecture with Volkswagen's new Touareg SUV. The Cayenne Turbo has it all: a twin-blown 4.5-liter V-8, six-speed Tiptronic S automatic transmission, full-time AWD with low-range transfer case, six-way height-adjustable suspension, electronically variable damping system, ABS, traction control, self-leveling, and much more. As you'd expect for a base price of $88,900, the interior packs high levels of luxury amenities and electronics and will swallow 63 cubic feet of cargo with the second-row seat folded flat.

Never heard of a Porsche X50? Most people haven't, as it's a Turbo option package, not a stand-alone model. The X50 package must be specified at build time and cannot be retrofitted. The substance of it resides beneath the Turbo's rear wing in the form of modified turbochargers (more boost), larger intercoolers, and more aggressive engine-control programming. It takes the standard Turbo's 420-horse rating up to 450 and creates a choice in between the Turbo (base MSRP of $116,200) and the 462-horsepower, rear-drive-only GT2 ($181,700). The upgrade costs an additional $17,880. Why buy an X50-ized Turbo instead of the GT2? It's not a question of better or worse, just choice, as the package allows you to buy an ultra-hot Porsche with all-wheel drive and a Tiptronic trans if you wish, neither of which is available on the lighter, maximum-performance GT2.

Off-roading the Turbo X50 means you probably missed an apex. But you'll want to take a Cayenne into the rough stuff for sure. Several of our editors have now done so and report it's the real deal. The watch-me-grow suspension adds meaningful ground clearance, and the low range means plenty of rock-crawling low-end torque and throttle control. The overhangs are short, the approach angles aggressive, and only the low-profile, 20-inch tire option is out of place among the rocks. And talk about brakes: The Porsche of SUVs takes no more room to stop than do most exotics.